A MODEL FOR PREDICTING THE GROWTH OF LISTERIA MONOCYTOGENES IN PACKAGED WHOLE MILK

• Published in: Journal of food process engineering Vol. 24; no. 4; pp. 231 - 251
• Main Authors: ALAVI, S.H., PURI, V.M., MOHTAR, R.H.
• Format: Magazine Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.10.2001; Blackwell
• Subjects: Biological and medical sciences; Finite element method; food contamination; Food industries; Food microbiology; food processing quality; Fundamental and applied biological sciences. Psychology; General aspects; Growth kinetics; Handling, storage, packaging, transport; heat transfer; Listeria monocytogenes; Mathematical models; microbiological quality; Microbiology; Microorganisms; milk; Milk and cheese industries. Ice creams; pasteurization; Physiology; plate count; prediction; spatial distribution; Statistical methods; temperature; Thermal effects; Performance evaluation; Microorganism growth; Temperature; Microbiological testing; Dairy product; Listeria monocytogenes; Shelf life; Time; Sterilized milk; Warehousing; Predictive microbiology; Distribution; Food preservation; Bacteria; Mathematical model; Biological contamination
• ISSN: 0145-8876; 1745-4530
• DOI: 10.1111/j.1745-4530.2001.tb00542.x

ABSTRACT Experiments were conducted to determine growth characteristics of Listeria monocytogenes in sterilized whole milk at nine temperatures in the range of 277.15 to 308.15K (4 to 35C). Based on these data, the parameter values of the Baranyi dynamic growth model were statistically determined. Finite element software, ANSYS, was used to determine temperature distributions in milk cartons subject to a time‐varying ambient temperature profile. The space‐time‐temperature data were input to the Baranyi dynamic growth model, to predict the microbial population density distribution and the average population density in the milk carton. The Baranyi dynamic growth model and the finite element model were integrated and validated using experimental results from inoculated sterilized whole milk in half‐gallon laminated paper cartons. In all experiments, the milk cartons were subjected to the same temperature profile as the Baranyi dynamic growth model. Experimental microbial counts were within predicted upper and lower bounds obtained using the integrated Baranyi dynamic growth and finite element models. In addition, the growth curve at the mean value of initial physiological state parameter for L. monocytogenes underpredicted the microbial growth (standard error = 0.54 log (cfu/mL) and maximum relative difference = 15.49%).